Production of phenol



July 28, 1925'.

- 1,547,725 c. H. BIBB v PRODUCTION OF PHEN OL v Filed June 18, 1925 AIL GASES OUTLET con DEN r4 n'mk: Acm TAN K CON DUIT AIR LINE INVENTOR CA RL/SLE H. 5188 A|R LINE DENZENE CONTAINER ATTORNEY Patented July 28, 1925. f

PATENT OFFICE.

GABLISLE E. 313B. 01' NEW BRUNSWICK, NEW J'EBS EY.

rnonuc'rrou or rnnuon.

Application filed June 18, 1923. Serial No. 645,966.

' To all whom it may concern:

and State of New Jersey, have invented cer- -2 is produced from same with oxldes is not at all 1' under proper conditions, it is Be it known that I, GARLTs n BIBB, a citizen of the United States, residmg in New Brunswick, in the county of Middlesex tain new and useful Improvements in the Production of Phenol, of which the following-is a full, clear, concise, and exact description.

In my Reissue Patent No. 15,789 issued March 11, 1924, covering a process of making aldehydes and other oxidation products, there is disclosed a process for producing alcohols, aldehydes and other oxidation products from hydrocarbons, and a specific example is given of converting methane into formaldehyde. The present invention is related to the general subject matter. of my above mentioned patent in that it c0ntemplates the production of phenol from ben zene.

Although the said patent relates generally to the production of' aldehydes and other oxidation products from hydrocarbons, it possible topredict therefrom that if a certain reaction takes place between a given compound and an aliphatic compound that a similar reaction will take place between the compound under similar conditions. It was the realization of this discovery which re-- i. e. by using sulted in the present invention, benzene instead of methane in the process set forth in the above mentioned patent, possible to produce phenol in the place of formaldehyde.

An object of the invention is the provision of a process whereby phenol may be made simply. and cheaply.

Another. object of. the invention is the provision of a process for producing phenol ;which employs largely constituents which are available. in great quantities and of such a character that the process can be readily practiced.

Another object of the invention is the modification or simplification of theprocess described in my aforesaid patent so as to make the general principles or steps thereof applicable to the Other objects-and advantages will be apscription.

In accordance with the invention, phenol benzene by mixing the of nitrogen, either alone parent from a reading of the following degiven compound and an aromatic production of' phenol.

or with air or oxygen; any substance that will liberate oxides of nitrogen under the conditions of the process hereinafter more fully described may be used in the place of free oxidesof nitrogen. The reactions between the mixture thus formed are effected by passing the same through a heated chamber. a

In carrying out the process air may be mixed with benzene vapor in a suitable manner, such as causing the air to pass through liquid benzene thus permitting the air to. become charged with the vapor of benzene, or the liquid benzene may be distilled or sprayed into the air stream. The resulting mixture, or the air before coming in contact with the benzene or the benzene vapor alone, is also mixed with a nitrogen oxide, or a mixture of nitrogen oxides, in any suitable manner such as passing the air throu h a solution of nitric acid or by distilling t e nitric acid into the air stream or by spraying it into the gaseous mixture.- Oxides of nitrogen may also be produced in the air stream by electrical; discharge or'by decomposition of such compounds that yield nitrous oxides, desired.

The resultlng m xture of air, benzene and Water may be added if diluted or concentrated nitric acid or the oxides of nitrogen is then led through a heated reaction chamber which preferably consists of a tube of silica, porcelain or fireclay. It may or may not be filled with such materials as, would facilitate the contact of the gasesiwithouttaking part in the reaction, for' example, zirconium oxide, etc.- The tube is preferably heated to a dull -re'dheat. The benzene in passing throughthe reaction chamber in the presence of the air and nitrogen oxides is partly oxidized to phenol, which iscarried out of thereaction chamber by the gases and condensed and separated from the air, unattacked benzene and by-products in a suitable manner.

The invention will be best understood by giving a specific example,.which comes within the variations justvdescribed and defined by the appended claims.

aluminum oxide,

In the accompanying drawing there, il-

benzene is placed 1 1 suspended ina water heated in any, suitable leaves the same consists of three parts by volume of air and one part of benzene vapor.

Nitric acid is placed within a tank which is also suspended in a hot water bath 9 adapted to be heated from steam line 10 controlled by a valve 11. Air 'is admitted into the tank 8 near the bottom thereof by means of a pipe 12 from a system including a control valve 13 and meter 14. The air charged with nitric acid fumes passes from tank 8 through a pipe 15 to a mixture conduit 16 connected with the container 1. The flow of the nitric acid fumes is so regulated that they constitute about 1% of the mixture in the conduit 16. The mixture of air, benzene vapor and nitric acid fumes is then passed through one or more silica tubes 17 which are preferably heated to about 7 00 C. in an electric furnace 18. The speed of the bases through the tube or reaction chamber 17 is so regulated that they remain therein approximately three seconds.

After passing through the furnace 18 the .hot gases are cooled to about 85 C. by circulating the same through .a condenser 19. At this stage in the process phenol will be separated out as a brownish liquid which gases should then contains a small amount of naphthalene, diphenyl, diphenylene oxide and traces of other by-products. The formation of the phenol may be observed by means of a sight glass20 interposed between the condenser 19 and a rece tacle 21 wherein the phenol may be collecte I The phenol is isolated by fractional distillation in a vacuum and can be readily purified by recrystallization. The remaining gaseous mixture, after being enriched in benzene and nitric acid, can again be assed through the heating tube 17 a num er of times until the concentration .of the oxygen gets too low to function eflicientlywhen the be obtained in any ape of operation may the method proved manner, as for example,

followed in my aforesaid Reissue Patent No.

15,789, wherein the gases leaving the condenser are subjected to a washing and scrubbing operation in a scrubber from which they are returned into the system from which they originated. Apparatus for this urpose may be inserted in the system by being connected to the outlet pipe 22 from whence the uncondensible or tail gases may be taken off. r

The proportions of benzene, air and nitric 8 'above a dull red heat,

be discarded. This cycle acid or nitrogen oxides may be widely varied with good results although it is preferred to use three volumes of air mixed with one volume of benzene vapors and a quantity of n1tr1c acid equal to one per cent by weight of the benzene used.

The temperature of the reaction chamber may be varied over a wide range. produced when the temperature of the reaction chamber is .cons1derably below a red heat and continues to. be formed far I although it is preferred to use the degree of heat given. Also the rate offlow of the gas may be widely varied with good results. However, its preferred to use a rate of flow which would cause the gases to remain in the furnace about three seconds. I

It is apparent from reference to the literature and consideration of the chemical reactions which take place in the reaction chamber 17 that the nitrogen oxides flmction merely as a catalyzer of the type that remains unchanged during the reaction pro,- mated by the use of he same and does not act as an oxidizing a ent. This contention is believed to be establlshed partly b the fact that the relatively small quantity 0 nitrogen oxides, as compared with the quantityflof benzene, used 1s insufiicient to oxidize the benzene. phenol from benzene and oxides of nitrogen according to this process, where the oxides of nitrogen do not function as catalyzers but as oxidizing agents, and although it is preferred to use them together with air and in such small amounts that they act as catalyzers it is not wished to be llmited to the catalytic action of oxides of nitrogen.

What is claimed is:

1. The step in the process of producing phenol comprising mixing benzene with oxides of nitrogen and heating the" mixture to a reaction temperature.

2. The step in the process of producing phenol comprising mixing benzene with oxides of nitrogen in the presence of oxygen and heating the mixture to a reaction tem-. perature.

3. The step in the process of producing phenol comprising mixing benzene with oxides of nitrogen in the presence of oxygen and heating the mixture to. a temperature of "about 700 C.

4:. A process of producing phenol com: prising mixing benzene,'oxygen and a gaseous catalyzer consisting of nitrogen oxides, the nitrogen oxides being used in relatively small uantities as compared with the quantity o benzene, heating the mixture to a reaction temperature and separating the phenol formed from the mixture.

5. The process of producing phenol comprising mixing benzine, air and a relatively small quantity of a gaseous catalyzer con- Phenol is It is however possible to make sisting of nitrogen oxidesiheating'the ture to a temperature of about; 700? (Land separating the phenol formetlifrom the mixture.

6. The

process of nroducing phenoifeorn prising mixing benzene; air and'nitrogen oxides, the nitrogen oxides being about 1% hy weight of the mixture of benzenefand air, heating the mixture ton. 'reaetion--.te'm-i: perature and separating from the mixture.

,mg We ght, heating" temperature and 7. A prising oxides, the quantity' ofnitrogen oxides pro'cesslof' producing phenolleom less than'theI-quanuty of benzene; by

formed from the" g subsc'rib' the phenol formed 1923.

In testimony whereof,.- I haVe hereunto mixture to. a reaction" P Q g the phenol Y mixing =benz'ene,, air and. nitro enfname this-15th day of June dARL'I'SLE H. BIBB.- 

